1. Field of the Invention
The present invention relates to an RF MEMS switch, and more particularly to an RF MEMS switch having asymmetrical spring rigidity to facilitate separation of the switch from a contacting surface when the switch is turned off.
2. Description of the Related Art
The MEMS (Micro Electro Mechanical System) refers to a micro electro-mechanical system manufactured through a semiconductor process. MEMS have been spotlighted recently because of their increasing application to a wider range of fields together with the advancement of mobile communication technologies. Of such MEMS products, a gyroscope, accelerometer, RF switch, and the like are currently applied to commercial products, and the developments of other diverse MEMS products are being accelerated.
The RF switch is an element that is frequently applied to signal routing, impedance matching networks, or the like in microwave or millimeter-wave bandwidth wireless communication terminals or systems.
In a conventional MMIC (Monolithic Microwave Integrated Circuit), GaAs FET's, PIN diodes, and the like are mainly used for implementation of the RF switch. However, the switch implemented with such elements has a drawback in that insertion loss is large while switched on and signal separation characteristics are poor when switched off.
Studies on mechanical switches have actively progressed in order to overcome such a drawback, and specifically, RF MEMS switches are required more than ever as the mobile communication terminal market has recently explosively expanded.
The RF MEMS switch is implemented such that signals are switched when a MEMS structure fabricated on a semiconductor substrate in a micro size contacts a signal electrode while moving, and signal transfers are cut off when the structure is spaced apart from the signal electrode.
However, such a conventional RF MEMS switch has a problem of difficulties in separating the switch from the contact surface when switched off due to the stiction force of the contact surface while switched on.